The present invention relates to a peptide having an anticancer activity. In particular, the present invention relates to a peptide showing a strong anticancer activity on hematologic malignancies as well as various carcinomas including skin cancer, cervical cancer, lung cancer, rectal cancer, and prostate cancer.
Most of the anticancer agents currently used have been developed by chemotherapy, and their pharmacological actions vary depending on the type of cancer (The pharmacological Basis of therapeutics, 18:1202, 1986), and many side effects due to toxicity of anticancer agents are the central problem in cancer treatment (Wonkwang Medical Sci. 3:13-34, 1987). In addition, anticancer agents effectively suppress the growth of cancer cells, whereas on occasion they penetrate into the normal tissue, and causes damage to normal tissue, in particular, to actively dividing cells. Thus, anticancer agents cause bone marrow depression, digestive disorders, and hair loss, and cancer cells also undergo mutations during growth, proliferation and metastasis so as to acquire resistance to anticancer agents, which generate severe problems in cancer treatment. Therefore, there is an urgent need for the development of effective anticancer agents to prevent such severe problems including toxicity to normal cells and drug resistance of cancer cells.
Since anticancer agents using antimicrobial peptides target substances that are different from the known anticancer agents, and enhance intracellular delivery and effects of other anticancer agents, they can be advantageously used in combination with other anticancer agents. At present, anticancer drug market exceeds 63 hundred million dollars annually, and annual research expenses relating to anticancer drugs reach 15 hundred million dollars. According to a pharmaceutical market analysis company, Datamonitor, annual sales of therapeutic peptides/proteins in 2010 are estimated to reach 590 hundred million dollars, resulted in a two-fold increase than that in 2001. Despite the promising prospects, antimicrobial peptides as an anticancer agent are still under the research phase, and are not yet commercialized. Thus, development of antimicrobial peptides as anticancer agents is a preoccupation of the anticancer drug market.
In addition to the function of the natural defense against invading pathogens, other functions of antimicrobial peptides have been recently revealed. In particular, many reports have been made on the anticancer activities of BMAP-28, HNP-1 (β-defensin), lactoferricin B, LL-37, magainin 2, melittin, tachyplesin I in the cell membranes. In Korea, antimicrobial peptides such as Gaegurin 5, Gaegurin 6, Kaisin I, and Kaisin II were reported to inhibit the growth of cancer cells in vivo. According to the current reports, the inability of antimicrobial peptides to distinguish cancer cells from normal cells, when injected to an organism having growing cancer cells, is a significant drawback. As an anticancer agent, the use of antimicrobial peptides with small size and strong anticancer activity is expected to usher in a new stage of the development of anticancer agents. Therefore, there is a continuous need to develop antimicrobial peptides which are able to distinguish cancer cells from normal cells and act only on cancer cells.